The study that identified those two pinnacle satisfaction periods, conducted by the Center for Economic Performance at the London School of Economics, involved a massive number of participants: 23,161 people, ranging in age from 17 to 85, reports Daily Mail.

What goes up must come down: after our early twenties, happiness declines on the way to our mid-fifties; then, after cycling back up through our late sixties, it falls again once we reach 75. If you’re having a midlife crisis — brooding over life choices and unfulfilled ambitions — buck up, better days are coming: the turnaround point is 55, according to the study, at which point happiness starts climbing once more (though that second harder turnaround after 75 sounds a little ominous).

Don’t take any of this as inevitable, however, because mental attitudes play an important role: Another recent study (via Scientific American) published in the Journal of Research in Personality that analyzed thousands of people across nearly four decades of life, age 16 forward, found that extroverted, emotionally stable young adults tended to be happier in retirement than young adults who’d been reticent or experienced an emotionally turbulent early adulthood.

Again, as Scientific American points out, those are just tendencies, not guarantees, and common sense (buttressed by research sense) about happiness and our psychological well-being’s ability to impact our health and longevity applies: Figuring out what makes you happy (really happy, that is) or improving unhappy life circumstances could well add time to our lives.